#include <iostream>

using namespace std;

class User {
private:
    string Account;
    string Password;
    string Mailbox;

public:
    User(string requiredAccount, string requiredPassword, string optionalMailbox = "")
        : Account(requiredAccount), Password(requiredPassword), Mailbox(optionalMailbox) {}

    string displayAccount() const {
        return Account;
    }

    string displayPassword() const {
        return Password;
    }

    string displayMailbox() const {
        return Mailbox;
    }
};

int main() {
    User user1("Yugo", "123456", "foxmail.com");
    User user2("MYQ", "654321");

    cout << "Account1 = " << user1.displayAccount() << endl;
    cout << "Password1 = " << user1.displayPassword() << endl;
    cout << "Mailbox1 = " << user1.displayMailbox() << endl;
    cout << "Account2 = " << user2.displayAccount() << endl;
    cout << "Password2 = " << user2.displayPassword() << endl;

    return 0;
}
